Granualr polyketone preparation

ABSTRACT

An improvement in the preparation of polyketones by FriedelCrafts synthesis, wherein the reaction mixture is dispersed into a heated fluid, prior to coagulation of the polyketone, to form a granular product.

United States Patent [191 Gander et al.

[451 Feb. 12, 1974 GRANUALR POLYKETONE PREPARATION [7 3] Assignee: E. I.du Pont de Nemours and Company, Wilmington, Del.

[22] Filed: Feb. 18, 1972 [2!] Appl. No.: 227,613

[52] US. Cl. 260/61 [51] Int. Cl C08g 23/00 [58] Field of Search 260/61[56] References Cited UNITED STATES PATENTS 2,521,288 9/l 95O Evers .L260/45 3,065,205 1 H1962 Bonner 260/63 3,385,825 5/1968 Goodman et al..260/6! 3,516,966 6/1970 Berr et al 260/47 3,660,317 5/1972 Masatsugu260/22 C 3,208,994 9/1965 Flodin 260/209 Primary Examiner-MelvinGoldstein Attorney, Agent, or Firm-Donald W. Huntley [57] ABSTRACT Animprovement in the preparation of polyketones by Friedel-Craftssynthesis, wherein the reaction mixture is dispersed into a heatedfluid, prior to coagulation of the polyketone, to form a granularproduct.

6 Claims, No Drawings PAIENTEDFEBIZW 3.791.890

SHEET 1 [IF 2 CONTROL w 1600 O: I) 8 0 m [200 [Z O. 800

400 o J a 0 o 0.2 0.4 0.6 0.8 L0 L2 L4 L6 L8 2.0

TIME (SECONDS) F 1g?! 2000 (I) Q: 3 I600 D 3 u.| I200 01 O. r

800 -u-% 3 I 400 o J 0 Q2 0.4 0.6 0.8 l.0 L2 L4 L6 I.8 2.0

TIME (SECONDS) Flgrfi INVENTOR.

RALPH W. LAWRENCE ALBERT J. SECCHI BY y ATTORNEY CHAMBER PRESSURE (PSIG)PAIENIEBFEBI 21914 3,7 1, 90

SHEET 2 OF 2 i 2000 (I) e g I600 D (O 8 0: I200 o- 5 800 m E I 400 UTIME (sscouos) Flgr] O 0.2 0.4 0.6 0.8- l.O 1.2 L4 L6 L8 2.0 TIME(SECONDS) INVENTOR. RALPH W. LAWRENCE ALBERT J. SECCHI A TTORNE) 1 AB OYKETQ E PRE ARATI BACKGROUND OF THE INVENTION Certain aromaticpolyketones recently made available in the art exhibit a wide variety ofphysical properties that make them particularly attractive for certaininsulating applications. Such polyketones are described, for example, inUS. Pat. Nos. 3,065,205, 3,441 ,538 and 3,442,857.

One difficulty previously encountered in the preparation of polymers ofthis type was the relatively intractable nature of the initialpolymer-catalyst complex upon formation. Previous attempts to deal withthe generally intractable state of the reaction product have includedpolymerizing the monomers in the presence of a soluble solid material topermit removing the product from the reaction medium and subsequentlyseparating the soluble material by leaching. However, none of theseprior techniques has proved entirely satisfactory.

SUMMARY OF THE INVENTION The instant invention provides an improvementthat permits the preparation of polyketones in granular form.

Specifically, the invention relates to an improvement in the process forthe preparation of polyketone compositions by bringing into contact, inan organic medium, diphenyl ether and a stoichiometric amount of atleast one compound selected from terephthalic and isophthalic acidchlorides with aluminum chloride catalyst and subsequently separatingthe polyketone from the resulting polymer-catalyst complex, whichimprovement comprises completing the reaction by dispersing the reactionmixture into a fluid maintained at a temperature of about from 50 to130C., the reaction mixture being dispersed a. prior to coagulation ofthe mixture; and

b. after the elapse of at least 25 percent of the time period betweenthe completion of the combination of reactants. including catalyst, andcoagulation of the reaction mixture.

DETAILED DESCRIPTION OF THE INVENTION The copolyketones prepared by theprocess of the instant invention are among those described in U. S. Pat.Nos. 3,065,205, 3,441,538 and 3,442,857. The specific copolyketones towhich the present invention relates have recurring units of thefollowing structural fori w g wherein the (EV moiety is U (T) and/or TheT:I ratio preferably varies from 902 to 30:70.

The preparation of the polyketones is begun using reactants and solventsof the type conventionally used in the art. Particularly useful solventsinclude odichlorobenzene, sym-tetrachloroethane, methylene chloride,dichloroethane and mixtures thereof. The aluminum chlorideFriedel-Crafts catalyst is generally added over a period of time as thelast component of the reaction mixture. It is understood, of course,that the addition rate of the catalyst is adjusted so that the entireamount of catalyst is incorporated prior to coagulation of the reactionmixture.

The reaction is generally begun at a first, lower temperature. Theinitial lower reaction temperature is desirable to maintain control overthe rate of the reaction, so that coagulation of the formed copolyketonedoes not occur before dispersion can be effected. A first reactiontemperature of about from 15 to 0C. has been found to be particularlyeffective; The term coagulation, as used in reference to the presentinvention, is that point at which the gelatinous polymer complex beginsto separate from the reaction mixture and coat the reaction vesselwalls.

In accordance with the instant process, the reaction mixture isdispersed into a fluid medium maintained at a temperature of at leastabout 50C., and preferably at least about C. In general, the fluid intowhich the reaction mixture is dispersed should be maintained at atemperature below 130C. and preferably below C. to minimize deleteriousside reactions. Accordingly, the fluid into which the reaction mixtureis dispersed should be maintained at a temperature of about from 50 toC., and preferably about from 70 to 120C. A dispersing fluid temperatureof at least about 100C. is especially preferred, particularly when agaseous fluid is used.

The fluid medium into which the reaction mixture is dispersed can be anygas or liquid in which the copolyketone formed is substantiallyunreactive at the temperature employed in the present process.Accordingly, the dispersing medium can comprise air or other gases suchas helium, nitrogen and oxygen or liquids including those conventionallyused as solvent systems in the preparation of these polyketones. Liquidsfor the dispersing medium can be the same as the initial reactionsolvent or different. Preferred liquids include aliphatic andcycloaliphatic saturated hydrocarbons, such as nonane, Nujol, decalinand decane; chlorinated aliphatic and cycloaliphatic saturatedhydrocarbons, such as tetrachloroethane, and dichlorocyclohexane,chlorinated aromatic hydrocarbons such as chlorobenzene,odichlorobenzene and p-dichlorobenzene.

A critical element of the process of the instant invention is that thereaction mixture be abruptly dispersed into the higher temperaturefluid. Accordingly, the volume of the high temperature fluid shouldcomprise at least 200 percent of the initial volume of the reactionmixture. The particular method of dispersing can vary widely dependingon the reaction procedure. In a batch process, for example, the entirereaction mixture, before coagulation, can be poured into a second vesselcontaining the high temperature liquid and therein abruptly dispersed,for example, by a high-speed stirrer. It is particularly preferred thatthe reaction mixture be transferred as a thin stream near the stirrer soas to prevent agglomeration on the walls of the second vessel.Alternatively, in a continuous reaction process, the reaction mixturecan be sprayed into air, gas or liquid maintained at the requiredtemperature increment. Another method of effecting the process of theinstant invention in a continuous operation involves introducing thereaction mixture into a stream of heated solvent at a point 'in the flow.of thereaction mixture before that at which coagulation of the polymerwould normally occur.

It has been found necessary to preheat the fluid into which the reactionmixture is dispersed, to effect a rise in temperature of the reactionmixture as abrupt as the dispersing itself. Accordingly, it would beunacceptable to inject heated dispersing liquid into the reactionsystem, or to combine the reaction mixture and dispersing fluid andsubsequently heat the combined fluids to the required temperature, sincethis would result in a gradual, rather than abrupt, temperature rise.While the mechanism of the instant process is not fully understood, itis believed that dispersion into a heated fluid in accordance with theinstant invention segregates the particles of copolymer that arebeginning to form in the initial reaction mixture, facilitates thecompletion of the reaction by elevated temperatures and, at the sametime, the dispersion prevents the agglomeration of these particles intothe gelatinous mass usually resulting from this type of polymerpreparation.

The improvement offered by the present invention greatly facilitates theproduction of polyketones of this type, since the resulting polymer isobtained in granular form. The production of granular particles by thisprocess eliminates the need for breaking up the rubbery, gelatinous massheretofore generally formed in the preparation of these polyketones,thus facilitating the purification of the polymer after formation.

lf reaction procedures arecarried out in accordance with the followingexamples, the indicated results will be obtained.

EXAMPLE 1 To a mixture of l 1.35 grams of diphenyl ether, 10.8] grams ofterephthaloyl chloride and 2.72 grams of isophthaloyl chloride in'areaction vessel containing 80 milliliters of o-dichlorobenzene solventmaintained at a temperature of C., is added 26.67 grams of anhydrousaluminum chloride over a period of'about minutes. The reaction isallowed to proceed until the elapse of about 14 minutes, which is 78percent of the time between completion of the catalyst addition andcoagulation. The mixture is thereupon poured as a thin stream into asecond reaction vessel at a point near the center of the vessel, withrapid stirring. The second vessel contains 250 milliliters ofdichlorobenzene having an initial temperature of about 82C. The reactionis allowed to come to completion over a 1 hour period and a uniform,granular polyketone-catalyst complex is obtained. The granules arereadily purified by filtering off the dichlorobenzene, washing severaltimes with absolute ethyl alcohol and vacuum drying at 50C.

EXAMPLE 2 The same initial reaction mixture used in Example I isprepared, and, prior to the start of coagulation of the polymer from thereaction mixture, the mixture is dispersed by spraying into an airstream heated to a temproduct is obtained.

EXAMPLE 3 I All glass apparatus used in this example is driedovernightin a 120 to 130C. oven and cooled in a dry box. Dry nitrogen issweptthrough the apparatus during assembly and continued until thereaction procedure is completed. Material transfers and all weighingsare done in a dry box.

To a tared l-liter reaction flask equipped with a stirrer, thermometer,and gas inlet for nitrogen sweep, is added approximately 71 grams (0.35mole) of a distilled :30 mixture of terephthaloyl and isophthaloylchlorides, and the charged flask is weighed to determine the exactamount of mixed acid chlorides used.

An amount of distilled diphenyl ether (approximately 59.5 grams)calculated to be stoichiometrically equivalent to the amount of mixedacid halides used, is weighed into a tared dropping funnel.

Anhydrous aluminum chloride (139 grams) is screened through a 40-meshstainless steel screen in a dry box and .is then weighed into a taredglass-stopped flask.

The reaction flask is set in place, the nitrogen sweep is begun, theagitator shaftis connected to a stirring motor, the dropping funnel isplaced on the flask, the diphenyl ether is added to the flask, and 350ml. of distilled ortho-dichlorobenzene is added to the reaction flaskthrough the dropping funnel. The charge is stirred to dissolve themonomers. The stirred charge is cooled to about from 5 to lOC. by usinga bath of water, ice and acetone.

The dropping funnel is removed from the reaction flask and replaced withan inclined glass screw tubular conveyor to which is attached the flaskcontaining the weighed quantity of aluminum chloride. The aluminumchloride is added to the reaction flask through the screw conveyor bymanually turning it; the rate of addi tion is adjusted to maintain thereaction solution temperature at 5 i 1C. and to complete the addition inabout 1.5 hrs.

vWhen the aluminum chloride addition is complete, the screw conveyor isreplaced by a fitting attached to a low vacuum to remove hydrogenchloride gas. The vacuum is applied gradually to minimize initialfoaming. The reaction mixture is stirred under vacuum for 15 min. Thevacuum is released by venting with nitrogen and agitation is stopped,while keeping the cooling bath in place.

The vacuum fitting in the reaction flask is replaced by a transfer tubeof 0.25 in. polyethylene tubing which dips to the bottom of the reactionflask and has a 0.125 in. (inside diameter) polyethylene connector fusedinto it as its discharge end. The discharge end of the tubing is placedinto a jacketed 3-liter resin kettle which has been equipped with astirrer, charged with 1,250 cc. of distilled orthodichlorobenzene andpreheated to C. by passing steam through the jacket. Three psig.nitrogen pressure is applied to the reaction flask in order to force thereaction mixture through the transfer tube and jet it into the hotdichlorobenzene. The expected polymer-catalyst complex precipitates as aslurry of small particles. Steam heating and stirring is continued for0.5 hr. after transfer to the resin kettle is completed.

The slurry is cooled to room temperature by passing water through thejacket of the kettle. Stirring is stopped, and the dichlorobenzeneisremoved by siphoning through a sintered glass tube. One liter ofdenatured ethanol is rapidly added to the polymer in the kettle, andstirring is resumed. The ensuing reaction of ethanol with thepolymercatalyst complex causes the temperature to rise to 40-45C. Thekettle is equipped with a reflux condenser, steam is again passedthrough the jacket, and the slurry is stirred and heated under refluxfor 0.5 hr. The slurry is again cooled, and the polymer collected byfiltration.

The granular polymer is washed by repeatedly slurrying in denaturedethanol containing hydrogen chloride and filtering, until a filtratediluted 50 percent with water and adjusted to pH 9 with dilute ammoniumhydroxide gives no precipitate of aluminum hydroxide. The polymer isfurther washed by repeatedly slurrying in denatured ethanol (containingno hydrogen chloride) until the filtrate gives only a weak test forchloride ion with silver nitrate solution. The polymer, identified asthe expected polyketone, is in a uniform, granular configuration, and isdried in a vacuum oven at 120 to 130C.

We claim:

1. In a process for the preparation of polyketone compositions ingranular form by bringing into contact, in an organic medium, diphenylether and a stoichiometric amount of at least one compound selected fromterephthalic and isophthalic acid chlorides with aluminum chloridecatalyst and subsequently separating the polyketone from the resultingpolymercatalyst com plex, the improvement which comprises completing thereaction by abruptly dispersing the reaction mixture into a highertemperature fluid maintained at a temperature of about from 50 to 130C,to effect an abrupt rise in temperature, the volume of said fluid beingat least 200 percent of the initial volume of the reaction mixture, thereaction mixture being dispersed a. prior to coagulation of the mixture;and

b. after the elapse of at least 25 percent of the time period betweenthe completion of the combination of reactants, including catalyst, andcoagulation of the reaction mixture.

2. A process of claim 1 wherein the fluid is a liquid solvent for themonomers used in the polyketone synthesis.

3. A process of claim 1 wherein the fluid is a gas.

4. A process of claim 3 wherein the fluid consists essentially of air.

5. A process of claim 1 wherein the temperature of the fluid ismaintained at about from to 120C.

6. A process of claim 4 wherein the temperature of the fluid ismaintained at a temperature of at least C.

structural formula.

UNITED STATES PATENT OFFICE V CERTIFICATE OF CORRECTION Tatent3,791,=890 Dated February 12 1974 I Frederick W. Gander et a1.Inventofls) I It is certified that error appears in the above-identifiedpatent .and that said Letters Patent are hereby corrected as shownbelow:

Column 1, about lirre 63, 1) should follow the Delete sheets 1 and2 ofthe patent.

Signed and sealed this 8th day of October 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. 7 C. MARSHALL DANN Commissioner of Patents Attesting Officer USCOMM-DC 60376-P69 11.5. GOVERNMENT PRINTING OFFICE: 930

FORM PO-IOSO (10-69)

2. A process of claim 1 wherein the fluid is a liquid solvent for themonomers used in the polyketone synthesis.
 3. A process of claim 1wherein the fluid is a gas.
 4. A process of claim 3 wherein the fluidconsists essentially of air.
 5. A process of claim 1 wherein thetemperAture of the fluid is maintained at about from 70* to 120*C.
 6. Aprocess of claim 4 wherein the temperature of the fluid is maintained ata temperature of at least 100*C.